Watts Radiant's Hydraulic Separator is designed to decouple the primary loop flow from the secondary, impede particle and sediment movement through a system, and to act as a point of air removal.Flow through the hydraulic separator is dependent on the resulting pressure differentials created by the circulators on either side. Circulators should always be arranged in a counter-flow orientation.Commonly used to simplify piping for condensing boilers, our separators are constructed from type -L copper with a stainless steel screen and brass air vent. A 3/4" brass drain, expansion tank tapping, and 5 temperature gauge/sensor wells are standard. Rated to 210 ?F at 100 psi.